Composite aggregate architecture

ABSTRACT

Techniques are provided for providing a storage abstraction layer for a composite aggregate architecture. A storage abstraction layer is utilized as an indirection layer between a file system and a storage environment. The storage abstraction layer obtains characteristic of a plurality of storage providers that provide access to heterogeneous types of storage of the storage environment (e.g., solid state storage, high availability storage, object storage, hard disk drive storage, etc.). The storage abstraction layer generates storage bins to manage storage of each storage provider. The storage abstraction layer generates a storage aggregate from the heterogeneous types of storage as a single storage container. The storage aggregate is exposed to the file system as the single storage container that abstracts away from the file system the management and physical storage details of data of the storage aggregate.

RELATED APPLICATIONS

This application claims priority to and is a continuation of U.S.application Ser. No. 15/467,293, filed on Mar. 23, 2017, now allowed,titled “COMPOSITE AGGREGATE ARCHITECTURE,” which is incorporated hereinby reference.

BACKGROUND

Many storage systems may provide clients with access to data storedwithin a plurality of storage devices. For example, a storage controllermay store client data within a set of storage devices that are locallyaccessible (e.g., locally attached to the storage controller) orremotely accessible (e.g., accessible over a network). A storageaggregate of storage may be generated from the set of storage devices(e.g., the storage aggregate may be stored across multiple storagedevices). The storage aggregate may be exported from a storage filesystem to a client. The storage aggregate may appear as a single storagecontainer to the client, such as a volume or logical unit number (lun).In this way, the aggregate abstracts away the details, from the client,of how the aggregate is physically stored amongst the set of storagedevices.

Some storage systems may store data within a multi-tiered storagearrangement. For example, the storage controller may store data within ahard disk drive tier and a solid state storage tier. The hard disk drivetier may be used as a capacity tier to store client data and forprocessing input/output operations. The solid state storage tier may beused as a cache for accelerating the processing of storage operations.Unfortunately, different classes of storage devices and media havedifferent characteristics and behaviors (e.g., latency, size, garbagecollection, efficiency of random storage operations, efficiency ofsequential storage operations, I/O access sizes such as a 4 kilobyte I/Oaccess size, etc.). Thus, a storage file system is unable to nativelycreate an aggregate from multiple heterogeneous storage devices andmedia.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a component block diagram illustrating an example clusterednetwork in accordance with one or more of the provisions set forthherein.

FIG. 2 is a component block diagram illustrating an example data storagesystem in accordance with one or more of the provisions set forthherein.

FIG. 3 is a flow chart illustrating an exemplary method of providing astorage abstraction layer for a composite aggregate architecture.

FIG. 4 is a component block diagram illustrating an exemplary computingdevice for providing a storage abstraction layer for a compositeaggregate architecture.

FIG. 5A is a component block diagram illustrating an exemplary computingdevice for providing a storage abstraction layer for a compositeaggregate architecture, where data is selectively stored within storageof a particular storage provider.

FIG. 5B is a component block diagram illustrating an exemplary computingdevice for providing a storage abstraction layer for a compositeaggregate architecture, where data is accumulated into a log.

FIG. 5C is a component block diagram illustrating an exemplary computingdevice for providing a storage abstraction layer for a compositeaggregate architecture, where accumulated data within a log is used togenerate a storage object that is sent to a storage provider forstorage.

FIG. 5D is a component block diagram illustrating an exemplary computingdevice for providing a storage abstraction layer for a compositeaggregate architecture, where data is accessed within a storage object.

FIG. 5E is a component block diagram illustrating an exemplary computingdevice for providing a storage abstraction layer for a compositeaggregate architecture, where garbage collection is performed.

FIG. 6 is an example of a computer readable medium in accordance withone or more of the provisions set forth herein.

DETAILED DESCRIPTION

Some examples of the claimed subject matter are now described withreference to the drawings, where like reference numerals are generallyused to refer to like elements throughout. In the following description,for purposes of explanation, numerous specific details are set forth inorder to provide an understanding of the claimed subject matter. It maybe evident, however, that the claimed subject matter may be practicedwithout these specific details. Nothing in this detailed description isadmitted as prior art.

One or more techniques and/or computing devices for providing a storageabstraction layer for a composite aggregate architecture are providedherein. The storage abstraction layer is provided as an indirectionlayer between a file system and a storage environment having a pluralityof heterogeneous types of storage and storage providers (e.g., thestorage abstraction layer reside below a file system layer). Forexample, the storage abstraction layer is configured to obtaincharacteristics of storage providers of the storage environment, such asof a hard disk drive tier storage provider, a solid state drive tierstorage provider, an object storage provider (e.g., a third party cloudstorage provider), a high availability (HA) storage provider (e.g., anHA pair of nodes), a shingled magnetic recording (SMR) storage provider,etc. Because the storage abstraction layer is below the file systemlayer, the storage abstraction layer is capable of perform operationsthat the file system layer is incapable of performing. For example, thestorage abstraction layer can generate a storage aggregate fromheterogeneous types of storage provided by different storage providers(e.g., an aggregate from storage of different classes of storage andmedia with different characteristics and behavior). The storageaggregate is exposed to the file system as though it is a single datacontainer from homogeneous storage. The storage abstraction layer candetermine where to store data (e.g., select a particular storageprovider to store certain data), when and how to move data betweendifferent storage providers, how to perform garbage collection on anindividual storage provider basis (e.g., freeing of storage blocks canbe done separately and per storage provider/device as opposed to by thefile system), and preserve storage efficiency of the file system such asdeduplication, encryption, and compression.

The storage abstraction layer can span any number of nodes, and a filesystem can reside on number of the nodes. New storage providers and/orstorage devices can be dynamically integrated with the storageabstraction layer, such as without the knowledge of or understanding bythe file system. Thus, new storage providers and/or storage devices thatare not natively compatible with the file system (e.g., the file systemperforms I/O access on 4 kilobyte chunks, whereas it is more efficientto send data to a distributed storage provider, such as a cloudprovider, in larger chunks such as in megabyte or gigabyte chunks fornetwork and processing efficiency) can still be used for the storageaggregate because the storage abstraction layer handles how and where tostore data.

To provide for providing a storage abstraction layer for a compositeaggregate architecture, FIG. 1 illustrates an embodiment of a clusterednetwork environment 100 or a network storage environment. It may beappreciated, however, that the techniques, etc. described herein may beimplemented within the clustered network environment 100, a non-clusternetwork environment, and/or a variety of other computing environments,such as a desktop computing environment. That is, the instantdisclosure, including the scope of the appended claims, is not meant tobe limited to the examples provided herein. It will be appreciated thatwhere the same or similar components, elements, features, items,modules, etc. are illustrated in later figures but were previouslydiscussed with regard to prior figures, that a similar (e.g., redundant)discussion of the same may be omitted when describing the subsequentfigures (e.g., for purposes of simplicity and ease of understanding).

FIG. 1 is a block diagram illustrating the clustered network environment100 that may implement at least some embodiments of the techniquesand/or systems described herein. The clustered network environment 100comprises data storage systems 102 and 104 that are coupled over acluster fabric 106, such as a computing network embodied as a privateInfiniband, Fibre Channel (FC), or Ethernet network facilitatingcommunication between the data storage systems 102 and 104 (and one ormore modules, component, etc. therein, such as, nodes 116 and 118, forexample). It will be appreciated that while two data storage systems 102and 104 and two nodes 116 and 118 are illustrated in FIG. 1, that anysuitable number of such components is contemplated. In an example, nodes116, 118 comprise storage controllers (e.g., node 116 may comprise aprimary or local storage controller and node 118 may comprise asecondary or remote storage controller) that provide client devices,such as host devices 108, 110, with access to data stored within datastorage devices 128, 130. Similarly, unless specifically providedotherwise herein, the same is true for other modules, elements,features, items, etc. referenced herein and/or illustrated in theaccompanying drawings. That is, a particular number of components,modules, elements, features, items, etc. disclosed herein is not meantto be interpreted in a limiting manner.

It will be further appreciated that clustered networks are not limitedto any particular geographic areas and can be clustered locally and/orremotely. Thus, in one embodiment a clustered network can be distributedover a plurality of storage systems and/or nodes located in a pluralityof geographic locations; while in another embodiment a clustered networkcan include data storage systems (e.g., 102, 104) residing in a samegeographic location (e.g., in a single onsite rack of data storagedevices).

In the illustrated example, one or more host devices 108, 110 which maycomprise, for example, client devices, personal computers (PCs),computing devices used for storage (e.g., storage servers), and othercomputers or peripheral devices (e.g., printers), are coupled to therespective data storage systems 102, 104 by storage network connections112, 114. Network connection may comprise a local area network (LAN) orwide area network (WAN), for example, that utilizes Network AttachedStorage (NAS) protocols, such as a Common Internet File System (CIFS)protocol or a Network File System (NFS) protocol to exchange datapackets, a Storage Area Network (SAN) protocol, such as Small ComputerSystem Interface (SCSI) or Fiber Channel Protocol (FCP), an objectprotocol, such as S3, etc. Illustratively, the host devices 108, 110 maybe general-purpose computers running applications, and may interact withthe data storage systems 102, 104 using a client/server model forexchange of information. That is, the host device may request data fromthe data storage system (e.g., data on a storage device managed by anetwork storage control configured to process I/O commands issued by thehost device for the storage device), and the data storage system mayreturn results of the request to the host device via one or more storagenetwork connections 112, 114.

The nodes 116, 118 on clustered data storage systems 102, 104 cancomprise network or host nodes that are interconnected as a cluster toprovide data storage and management services, such as to an enterprisehaving remote locations, cloud storage (e.g., a storage endpoint may bestored within a data cloud), etc., for example. Such a node in theclustered network environment 100 can be a device attached to thenetwork as a connection point, redistribution point or communicationendpoint, for example. A node may be capable of sending, receiving,and/or forwarding information over a network communications channel, andcould comprise any device that meets any or all of these criteria. Oneexample of a node may be a data storage and management server attachedto a network, where the server can comprise a general purpose computeror a computing device particularly configured to operate as a server ina data storage and management system.

In an example, a first cluster of nodes such as the nodes 116, 118(e.g., a first set of storage controllers configured to provide accessto a first storage aggregate comprising a first logical grouping of oneor more storage devices) may be located on a first storage site. Asecond cluster of nodes, not illustrated, may be located at a secondstorage site (e.g., a second set of storage controllers configured toprovide access to a second storage aggregate comprising a second logicalgrouping of one or more storage devices). The first cluster of nodes andthe second cluster of nodes may be configured according to a disasterrecovery configuration where a surviving cluster of nodes providesswitchover access to storage devices of a disaster cluster of nodes inthe event a disaster occurs at a disaster storage site comprising thedisaster cluster of nodes (e.g., the first cluster of nodes providesclient devices with switchover data access to storage devices of thesecond storage aggregate in the event a disaster occurs at the secondstorage site).

As illustrated in the clustered network environment 100, nodes 116, 118can comprise various functional components that coordinate to providedistributed storage architecture for the cluster. For example, the nodescan comprise network modules 120, 122 and disk modules 124, 126. Networkmodules 120, 122 can be configured to allow the nodes 116, 118 (e.g.,network storage controllers) to connect with host devices 108, 110 overthe storage network connections 112, 114, for example, allowing the hostdevices 108, 110 to access data stored in the distributed storagesystem. Further, the network modules 120, 122 can provide connectionswith one or more other components through the cluster fabric 106. Forexample, in FIG. 1, the network module 120 of node 116 can access asecond data storage device by sending a request through the disk module126 of node 118.

Disk modules 124, 126 can be configured to connect one or more datastorage devices 128, 130, such as disks or arrays of disks, flashmemory, or some other form of data storage, to the nodes 116, 118. Thenodes 116, 118 can be interconnected by the cluster fabric 106, forexample, allowing respective nodes in the cluster to access data on datastorage devices 128, 130 connected to different nodes in the cluster.Often, disk modules 124, 126 communicate with the data storage devices128, 130 according to the SAN protocol, such as SCSI or FCP, forexample. Thus, as seen from an operating system on nodes 116, 118, thedata storage devices 128, 130 can appear as locally attached to theoperating system. In this manner, different nodes 116, 118, etc. mayaccess data blocks through the operating system, rather than expresslyrequesting abstract files.

It should be appreciated that, while the clustered network environment100 illustrates an equal number of network and disk modules, otherembodiments may comprise a differing number of these modules. Forexample, there may be a plurality of network and disk modulesinterconnected in a cluster that does not have a one-to-onecorrespondence between the network and disk modules. That is, differentnodes can have a different number of network and disk modules, and thesame node can have a different number of network modules than diskmodules.

Further, a host device 108, 110 can be networked with the nodes 116, 118in the cluster, over the storage networking connections 112, 114. As anexample, respective host devices 108, 110 that are networked to acluster may request services (e.g., exchanging of information in theform of data packets) of nodes 116, 118 in the cluster, and the nodes116, 118 can return results of the requested services to the hostdevices 108, 110. In one embodiment, the host devices 108, 110 canexchange information with the network modules 120, 122 residing in thenodes 116, 118 (e.g., network hosts) in the data storage systems 102,104.

In one embodiment, the data storage devices 128, 130 comprise volumes132, which is an implementation of storage of information onto diskdrives or disk arrays or other storage (e.g., flash) as a file-systemfor data, for example. In an example, a disk array can include alltraditional hard drives, all flash drives, or a combination oftraditional hard drives and flash drives. Volumes can span a portion ofa disk, a collection of disks, or portions of disks, for example, andtypically define an overall logical arrangement of file storage on diskspace in the storage system. In one embodiment a volume can comprisestored data as one or more files that reside in a hierarchical directorystructure within the volume.

Volumes are typically configured in formats that may be associated withparticular storage systems, and respective volume formats typicallycomprise features that provide functionality to the volumes, such asproviding an ability for volumes to form clusters. For example, where afirst storage system may utilize a first format for their volumes, asecond storage system may utilize a second format for their volumes.

In the clustered network environment 100, the host devices 108, 110 canutilize the data storage systems 102, 104 to store and retrieve datafrom the volumes 132. In this embodiment, for example, the host device108 can send data packets to the network module 120 in the node 116within data storage system 102. The node 116 can forward the data to thedata storage device 128 using the disk module 124, where the datastorage device 128 comprises volume 132A. In this way, in this example,the host device can access the volume 132A, to store and/or retrievedata, using the data storage system 102 connected by the storage networkconnection 112. Further, in this embodiment, the host device 110 canexchange data with the network module 122 in the node 118 within thedata storage system 104 (e.g., which may be remote from the data storagesystem 102). The node 118 can forward the data to the data storagedevice 130 using the disk module 126, thereby accessing volume 1328associated with the data storage device 130.

It may be appreciated that providing a storage abstraction layer for acomposite aggregate architecture may be implemented within the clusterednetwork environment 100. In an example, a storage abstraction layer maygenerate and maintain a first storage bin to manage the data storagedevice 128 of the node 116 (e.g., a first storage provider) and a secondstorage bin to manage the data storage device 130 of the node 118 (e.g.,a second storage provider). The storage abstraction layer may be anindirection layer underneath a storage file system layer. The storageabstraction layer generates and exposes a single storage aggregate,derived from the data storage device 128 and the data storage device130, to a file system notwithstanding the data storage devices 128, 130being heterogeneous types of storage. It may be appreciated thatproviding a storage abstraction layer for a composite aggregatearchitecture may be implemented for and/or between any type of computingenvironment, and may be transferrable between physical devices (e.g.,node 116, node 118, a desktop computer, a tablet, a laptop, a wearabledevice, a mobile device, a storage device, a server, etc.) and/or acloud computing environment (e.g., remote to the clustered networkenvironment 100).

FIG. 2 is an illustrative example of a data storage system 200 (e.g.,102, 104 in FIG. 1), providing further detail of an embodiment ofcomponents that may implement one or more of the techniques and/orsystems described herein. The data storage system 200 comprises a node202 (e.g., nodes 116, 118 in FIG. 1), and a data storage device 234(e.g., data storage devices 128, 130 in FIG. 1). The node 202 may be ageneral purpose computer, for example, or some other computing deviceparticularly configured to operate as a storage server. A host device205 (e.g., 108, 110 in FIG. 1) can be connected to the node 202 over anetwork 216, for example, to provide access to files and/or other datastored on the data storage device 234. In an example, the node 202comprises a storage controller that provides client devices, such as thehost device 205, with access to data stored within data storage device234.

The data storage device 234 can comprise mass storage devices, such asdisks 224, 226, 228 of a disk array 218, 220, 222. It will beappreciated that the techniques and systems, described herein, are notlimited by the example embodiment. For example, disks 224, 226, 228 maycomprise any type of mass storage devices, including but not limited tomagnetic disk drives, flash memory, and any other similar media adaptedto store information, including, for example, data (D) and/or parity (P)information.

The node 202 comprises one or more processors 204, a memory 206, anetwork adapter 210, a cluster access adapter 212, and a storage adapter214 interconnected by a system bus 242. The data storage system 200 alsoincludes an operating system 208 installed in the memory 206 of the node202 that can, for example, implement a Redundant Array of Independent(or Inexpensive) Disks (RAID) optimization technique to optimize areconstruction process of data of a failed disk in an array.

The operating system 208 can also manage communications for the datastorage system, and communications between other data storage systemsthat may be in a clustered network, such as attached to a cluster fabric215 (e.g., 106 in FIG. 1). Thus, the node 202, such as a network storagecontroller, can respond to host device requests to manage data on thedata storage device 234 (e.g., or additional clustered devices) inaccordance with these host device requests. The operating system 208 canoften establish one or more file systems on the data storage system 200,where a file system can include software code and data structures thatimplement a persistent hierarchical namespace of files and directories,for example. As an example, when a new data storage device (not shown)is added to a clustered network system, the operating system 208 isinformed where, in an existing directory tree, new files associated withthe new data storage device are to be stored. This is often referred toas “mounting” a file system.

In the example data storage system 200, memory 206 can include storagelocations that are addressable by the processors 204 and adapters 210,212, 214 for storing related software application code and datastructures. The processors 204 and adapters 210, 212, 214 may, forexample, include processing elements and/or logic circuitry configuredto execute the software code and manipulate the data structures. Theoperating system 208, portions of which are typically resident in thememory 206 and executed by the processing elements, functionallyorganizes the storage system by, among other things, invoking storageoperations in support of a file service implemented by the storagesystem. It will be apparent to those skilled in the art that otherprocessing and memory mechanisms, including various computer readablemedia, may be used for storing and/or executing application instructionspertaining to the techniques described herein. For example, theoperating system can also utilize one or more control files (not shown)to aid in the provisioning of virtual machines.

The network adapter 210 includes the mechanical, electrical andsignaling circuitry needed to connect the data storage system 200 to ahost device 205 over a network 216, which may comprise, among otherthings, a point-to-point connection or a shared medium, such as a localarea network. The host device 205 (e.g., 108, 110 of FIG. 1) may be ageneral-purpose computer configured to execute applications. Asdescribed above, the host device 205 may interact with the data storagesystem 200 in accordance with a client/host model of informationdelivery.

The storage adapter 214 cooperates with the operating system 208executing on the node 202 to access information requested by the hostdevice 205 (e.g., access data on a storage device managed by a networkstorage controller). The information may be stored on any type ofattached array of writeable media such as magnetic disk drives, flashmemory, and/or any other similar media adapted to store information. Inthe example data storage system 200, the information can be stored indata blocks on the disks 224, 226, 228. The storage adapter 214 caninclude input/output (I/O) interface circuitry that couples to the disksover an I/O interconnect arrangement, such as a storage area network(SAN) protocol (e.g., Small Computer System Interface (SCSI), iSCSI,hyperSCSI, Fiber Channel Protocol (FCP)). The information is retrievedby the storage adapter 214 and, if necessary, processed by the one ormore processors 204 (or the storage adapter 214 itself) prior to beingforwarded over the system bus 242 to the network adapter 210 (and/or thecluster access adapter 212 if sending to another node in the cluster)where the information is formatted into a data packet and returned tothe host device 205 over the network 216 (and/or returned to anothernode attached to the cluster over the cluster fabric 215).

In one embodiment, storage of information on disk arrays 218, 220, 222can be implemented as one or more storage volumes 230, 232 that arecomprised of a cluster of disks 224, 226, 228 defining an overalllogical arrangement of disk space. The disks 224, 226, 228 that compriseone or more volumes are typically organized as one or more groups ofRAIDs. As an example, volume 230 comprises an aggregate of disk arrays218 and 220, which comprise the cluster of disks 224 and 226.

In one embodiment, to facilitate access to disks 224, 226, 228, theoperating system 208 may implement a file system (e.g., write anywherefile system) that logically organizes the information as a hierarchicalstructure of directories and files on the disks. In this embodiment,respective files may be implemented as a set of disk blocks configuredto store information, whereas directories may be implemented asspecially formatted files in which information about other files anddirectories are stored.

Whatever the underlying physical configuration within this data storagesystem 200, data can be stored as files within physical and/or virtualvolumes, which can be associated with respective volume identifiers,such as file system identifiers (FSIDs), which can be 32-bits in lengthin one example.

A physical volume corresponds to at least a portion of physical storagedevices whose address, addressable space, location, etc. doesn't change,such as at least some of one or more data storage devices 234 (e.g., aRedundant Array of Independent (or Inexpensive) Disks (RAID system)).Typically the location of the physical volume doesn't change in that the(range of) address(es) used to access it generally remains constant.

A virtual volume, in contrast, is stored over an aggregate of disparateportions of different physical storage devices. The virtual volume maybe a collection of different available portions of different physicalstorage device locations, such as some available space from each of thedisks 224, 226, and/or 228. It will be appreciated that since a virtualvolume is not “tied” to any one particular storage device, a virtualvolume can be said to include a layer of abstraction or virtualization,which allows it to be resized and/or flexible in some regards.

Further, a virtual volume can include one or more logical unit numbers(LUNs) 238, directories 236, Qtrees 235, and files 240. Among otherthings, these features, but more particularly LUNS, allow the disparatememory locations within which data is stored to be identified, forexample, and grouped as data storage unit. As such, the LUNs 238 may becharacterized as constituting a virtual disk or drive upon which datawithin the virtual volume is stored within the aggregate. For example,LUNs are often referred to as virtual drives, such that they emulate ahard drive from a general purpose computer, while they actually comprisedata blocks stored in various parts of a volume.

In one embodiment, one or more data storage devices 234 can have one ormore physical ports, wherein each physical port can be assigned a targetaddress (e.g., SCSI target address). To represent respective volumesstored on a data storage device, a target address on the data storagedevice can be used to identify one or more LUNs 238. Thus, for example,when the node 202 connects to a volume 230, 232 through the storageadapter 214, a connection between the node 202 and the one or more LUNs238 underlying the volume is created.

In one embodiment, respective target addresses can identify multipleLUNs, such that a target address can represent multiple volumes. The I/Ointerface, which can be implemented as circuitry and/or software in thestorage adapter 214 or as executable code residing in memory 206 andexecuted by the processors 204, for example, can connect to volume 230by using one or more addresses that identify the one or more LUNs 238.

It may be appreciated that providing a storage abstraction layer for acomposite aggregate architecture may be implemented for the data storagesystem 200. In an example, a storage abstraction layer may generate andmaintain a first storage bin to manage storage of the node 202 (e.g., afirst storage provider). The storage abstraction layer may maintainother storage bins for managing storage (e.g., storage devices withdifferent characteristics than the storage of the node 202) of othernodes. In this way, the storage abstraction layer generates and exposesa single storage aggregate, derived from storage of the node 202 and/orstorage other storage providers, to a file system. It may be appreciatedthat providing a storage abstraction layer for a composite aggregatearchitecture may be implemented for and/or between any type of computingenvironment, and may be transferrable between physical devices (e.g.,node 202, host device 205, a desktop computer, a tablet, a laptop, awearable device, a mobile device, a storage device, a server, etc.)and/or a cloud computing environment (e.g., remote to the node 202and/or the host device 205).

One embodiment of providing a storage abstraction layer for a compositeaggregate architecture is illustrated by an exemplary method 300 of FIG.3. A storage abstraction layer (e.g., a set of classes, functionality,protocol functionality, policies, network communication functionality,storage management functionality, etc. that can provide a transparentinterface to various storage providers) can be utilized as anindirection layer between a file system (e.g., a storage file system)and a storage environment (e.g., storage providers accessible over oneor more networks). The storage abstraction layer can abstract away thedetails regarding where and how data is stored amongst a plurality ofdifferent types of storage providers and storage devices. For example,the storage abstraction layer may expose a storage aggregate/pool thatappears to be a single storage container to the file system. Thus, thefile system merely reads and writes to that single storage container.However, the storage abstraction layer intercepts the read and writerequests, and determines where and how to store and retrieve data.

At 302, the storage abstraction layer obtains characteristics of aplurality of storage providers that provide access to heterogeneoustypes of storage of the storage environment. The characteristics mayrelate to latency, storage capacity, type of storage device/media (e.g.,magnetic storage, solid state/flash storage, cloud storage, highavailability storage, memory or NVRAM, locally attached storage, remotestorage, shingled magnetic recording storage, etc.), I/O access size,garbage collection policies, supported storage access protocols,encryption used, how data is stored (e.g., stored as blocks of datahaving a particular size), how data is referenced/indexed (e.g.,referenced by an object ID and an offset within the object ID forparticular data, referenced by a physical block number, referenced by alogical block number, referenced by a file name, referenced by anoffset, etc.), etc.

In an example, the storage abstraction layer may communicate with afirst node and a second node (e.g., a high availability node pairing)that provide high availability access to locally attached data storagein order to obtain characteristics of the nodes and their storage. Inanother example, the storage abstraction layer may communicate, over anetwork, to a distributed object storage provider (e.g., cloud storageprovided by a third party provider) that provides object storage inorder to obtain characteristics of the distributed storage provider andthe object storage. In this way, a variety of storage providers may beaccessed in order to obtain the characteristics. Because the storageabstraction layer can interface with multiple different types of storageproviders, the file system can be hosted across any number of nodes andthe storage abstraction layer can create aggregates from storage hostedby multiple different types of nodes and storage providers.

At 304, a first storage bin may be generated, by the storage abstractionlayer, to manage first storage of a first storage provider. The firststorage bin may be configured based upon first characteristics of thefirst storage provider. For example, the first storage bin may beconfigured to access the first storage provider (e.g., a solid statestorage provider) using a particular protocol and I/O access size usedby the first storage provider. The first storage bin may be configuredto use certain types of compression, encryption, garbage collectionpolicies, data formats, and/or data reference formats (e.g., refer todata by physical block numbers, logical block numbers, file names,object identifiers, offsets, etc.) associated with the first storageprovider.

At 306, a second storage bin may be generated, by the storageabstraction layer, to manage second storage of a second storageprovider. The second storage bin may be configured based upon secondcharacteristics of the second storage provider. For example, the secondstorage bin may be configured to access the second storage provider(e.g., a cloud storage provider) using a protocol and/or I/O access sizeused by the second storage provider. The second storage bin may beconfigured to use certain types of compression, encryption, garbagecollection policies, data formats, and/or data reference formats (e.g.,refer to data by physical block numbers, logical block numbers, filenames, object identifiers, offsets, etc.) associated with the secondstorage provider.

It may be appreciated that the storage abstraction layer may generateany number of storage bins for any number of storage providers for whichthe storage abstraction layer is to abstract away the details ofphysically storing data from the file system. The storage providers maystore data in different manners and provide access to data in differentways. For example, the first storage provider may support a first I/Osize such as a 4 kilobyte I/O size for reading/writing data. Incontrast, the second storage provider may support a second I/O size suchas an unconstrained range up to 1 gigabyte. For example, it may be moreefficient to send data to the cloud storage provider in larger chunkssuch as chunks in a megabyte or gigabyte range, which may moreefficiently utilize network bandwidth and processing resources. Eventhough the file system may merely support the first I/O size, thestorage abstraction layer can use the second storage bin as anintermediary interface to handle the details of how data will be sentto, stored within, and accessed from the cloud storage provider usingthe second I/O size.

At 308, a storage aggregate is generated, by the storage abstractionlayer, from the first storage having a first storage type (e.g., solidstate drive storage provided by the first storage provider), the secondstorage having a second storage type different than the first storagetype (e.g., object storage provided by the cloud storage provider),and/or other storage from other storage providers. The storageabstraction layer will use individual storage bins to manage where andhow to store and access data within each storage of each storageprovider. At 310, the storage aggregate is exposed to the file system asa single storage container. For example, the storage abstraction layermay expose the storage aggregate as a single volume, a single LUN, orother data container while abstracting away the notion that the storageaggregate is actually composed of portions of storage from multiplestorage provider. In an example, the storage abstraction layer mayexpose merely a subset of characteristics of the storage providers tothe file system (e.g., a type of storage may be exposed, but not othercharacteristics like how old/stale data blocks are freed, overwritten,etc.).

The storage abstraction layer is utilized to selectively store aplurality of data from the file system through storage bins tocorresponding storage of the plurality of storage providers based uponcharacteristics of data and characteristics of storage providers. Acharacteristic may corresponding to a sequential access characteristic,a random access characteristic, a user data characteristic, a metadatacharacteristic (e.g., a replication policy, a backup policy, a LUNconfiguration, an identification of a partner node, and/or othermetadata used by the file system or nodes for operation), a frequentlyaccessed characteristic (e.g., hot data having an accessfrequency/pattern above a threshold), an infrequently accessedcharacteristic (e.g., cold data having an access frequency/pattern belowthe threshold), etc. The storage abstraction layer is configured todetermine which type of storage and storage provider is better suited tostore certain types of data (e.g., a cloud storage provider may be morecost effective to store infrequently accessed user data, whereas ashingled magnetic recording storage provider may be better forfrequently accessed metadata and a high availability storage providerwith additional redundancy may be better for mission critical data).

In an example, a request may be received from the file system to storefirst data within the storage aggregate. Because the storage aggregateis exposed as a single storage container, the request does not specifywhich storage provider and/or type of storage the first data is to bestored. Accordingly, the storage abstraction layer may selectively storethe first data, through the first storage bin, into a first storagelocation of the first storage and not into the second storage based upona data characteristic of the first data corresponding to acharacteristic of the first storage provider (e.g., the first storagemay be more efficient for storing sequentially accessed data than thesecond storage). At some point in time, the storage abstraction layermay determine that the first data should be moved from the first storagelocation within the first storage to a second storage location withinthe second storage of the second storage provider. Accordingly, thestorage abstraction layer moves the first data from the first storage tothe second storage at the second storage location, which may beperformed transparent to the file system since the storage abstractionlayer abstracts away the physical storage details of data of the storageaggregate from the file system.

An overwrite request, to overwrite the first data with new data, may bereceived by the storage abstraction layer from the file system. In anexample where the file system is a write anywhere file system, the newdata may not be written to a current location of the first data (e.g.,the second storage location of the second storage) but is written to adifferent location that is free/available. Thus, at some point, thefirst data at that current location will need to be garbage collected sothat the current location is freed and available to store other datasince the first data at the second storage location has become staleonce the new data is written to the different location. The storageabstraction layer may store the new data of the overwrite request into athird storage location as new first data. The third storage location maybe within the first storage where the first data was previously locatedbefore being moved/migrated, or within the second storage where thefirst data is currently located at the second storage location, orwithin any other storage of any other storage provider. The secondstorage bin may be used to mark the first data at the second storagelocation for garbage collection so that the second storage location canbe freed and available for data storage since the new first data at thethird storage location is a most up-to-date version. Garbage collectionmay be facilitated on a storage provider by storage provider basis in amanner that is transparent to the file system (e.g., different garbagecollection policies may be implemented for different storage providers).

In an example, the storage abstraction layer may track various metricsregarding data, such as a first frequency of access to data (A) withinthe first storage, a second frequency of access to data (B) within thesecond storage, etc. Responsive to the storage abstraction layerdetermining that the first frequency of access is below a threshold setby the first storage bin for the first storage, the data (A) may beaccumulated from the first storage into a log of the first storage bin.Responsive to the storage abstraction layer determining that the secondfrequency of access is below a threshold set by the second storage binfor the second storage, the data (B) may be accumulated from the secondstorage into a second log of the second storage bin.

The storage abstraction layer may determine that a threshold amount ofdata has been accumulated into the log of the first storage bin for thefirst storage (e.g., a threshold amount of cold data may be collectedfrom the solid state drive storage of the solid state drive storageprovider into the first storage bin). Accordingly, the storageabstraction layer may generate a storage object, corresponding to a dataformat of the second storage (e.g., the cloud storage provider may storedata within objects), comprising the accumulated data from the log suchas the data (A). In this way, the storage object may comprise data ofvarious files, directories, applications, etc. The storage abstractionlayer sends the storage object, through the second storage bin, to thesecond storage provider for storage within the second storage. It may beappreciated that accumulated data from any type of storage provider maybe used to generate any type of data object/container that is compatiblewith a destination for the accumulated data (e.g., a block based dataformat, a file, a LUN, a storage object, a database file, etc.). Thestorage abstraction layer may populate an object metafile with one ormore entries indication what data is stored within the storage object(e.g., data references used by the file system to reference the datasuch as virtual block numbers), and object identifier of the storageobject, and offsets of such data.

The storage abstraction layer may receive an access request for the data(A) from the file system (e.g., the file system may be unaware of thelocation of the data (A) as being within the storage object now storedat the second storage of the second storage provider). In an example,the access request comprises a physical volume block number or any otheridentifier used by the file system to reference the data (A) within thestorage aggregate. The storage abstraction layer may query the objectmetafile using the physical volume block number to identify an objectidentifier of the storage object and an offset of the data (A) withinthe storage object. The object identifier and the offset may be used toprovide access through the second storage bin to the data (A) within thestorage object stored within the second storage by the second storageprovider. In this way, the file system may access the data (A)notwithstanding the data (A) being comprised within the storage object,along with other data that may be unrelated, that is now stored withinthe second storage.

The storage abstraction layer may track reference counts of referencesto data stored within the storage of the storage providers (e.g., thestorage abstraction layer may provide its own garbage collection forindividual storage of each storage provider as opposed to adhering towhat is tracked by the file system for the storage aggregate). Forexample, the first storage bin may be used to track reference counts ofreferences to data within the first storage. The reference counts may beused to free data, with reference counts of zero, from the first storagebecause such data may be stale/unused due to new data being writtenelsewhere by a write anywhere file system that does not overwritecurrent locations of data with new data but writes the new data toopen/free storage locations.

The storage abstraction layer may be configured to preserve storageefficiency of the file system. In an example, the storage abstractionlayer may receive compressed data from the file system. The storageabstraction layer may store the compressed data, in a compressed state,within the first storage. Alternatively, uncompressed data that is to becompressed may be received from the file system or retrieved from astorage provider. Accordingly, the storage abstraction layer may performcompression upon the uncompressed data (e.g., within a storage bin orlog), and then send the compressed data to a particular storageprovider.

In another example, the storage abstraction layer may receive encrypteddata from the file system. The storage abstraction layer may store theencrypted data, in an encrypted state, within the first storage.Alternatively, unencrypted data that is to be encrypted may be receivedfrom the file system or retrieved from a storage provider. Accordingly,the storage abstraction layer may encrypted the unencrypted data (e.g.,within a storage bin or log), and then send the encrypted data to aparticular storage provider.

In another example, the storage abstraction layer may preservededuplication provided by the file system. For example, the storageabstraction layer may maintain its own reference count of references todata.

In an example, if data is to be moved between storage providers, thenthe data may be placed into a log and then compression, encryption,and/or other storage efficiency functionality may be performed upon thedata within the log in order to preserve such functionality.

FIG. 4 illustrates an example of a system 400 having a composite storagearchitecture. A file system may operate at a storage file system layer404. Clients may access the file system through a storage file systemaccess layer 402. For example, a client may send read commands, writecommands, create commands, and/or other commands to the file systemthrough the storage file system access layer 402. A storage abstractionlayer 406 is provided as an indirection/intermediate layer between thefile system, such as the storage file system layer 404, and a storageenvironment 428. The storage abstraction layer 406 is underneath thestorage file system layer 404.

The storage abstraction layer 406 may obtain characteristics of storageproviders within the storage environment 428. Based upon thosecharacteristics, the storage abstraction layer 406 creates storage binsfor managing storage of the storage providers. Each storage bin istailored to a particular storage provider because types of storageprovided by each storage provider may have different characteristics(e.g., certain storage may perform better for random access orsequential access; certain storage may provide better redundancy;certain storage providers may provide more security; certain storageproviders may provide higher availability to data; etc.). For example, asolid state drive storage bin 408 may be generated for a solid statedrive storage provider 418. The solid state drive storage bin 408 maydetermine where and how to store data within solid state drive storageof the solid state drive storage provider 418, set what protocols touse, set what garbage collection technique to use, set thresholds fordetermining cold/hot data for the solid state drive storage provider418, set what compression to use, set redundancy polices, set securitypolicies, set what I/O access size to use, set what data format to use,determine how to reference/identify particular data, etc.

A hard disk drive storage bin 410 may be generated for a hard disk drivestorage provider 420. The hard disk drive storage bin 410 may determinewhere and how to store data within hard disk drive storage of the harddisk drive storage provider 420, set what protocols to use, set whatgarbage collection technique to use, set thresholds for determiningcold/hot data for the hard disk drive storage provider 420, set whatcompression to use, set redundancy polices, set security policies, setwhat I/O access size to use, set what data format to use, determine howto reference/identify particular data, etc.

An object storage bin 412 may be generated for an object storageprovider 422 (e.g., a cloud storage provider that stores data withinobjects). The object storage bin 412 may determine where and how tostore data within object storage of the object storage provider 422, setwhat protocols to use, set what garbage collection technique to use, setthresholds for determining cold/hot data for the object storage provider422, set what compression to use, set redundancy polices, set securitypolicies, set what I/O access size to use, set what data format to use,determine how to reference/identify particular data, etc.

A shingled magnetic recording storage bin 414 may be generated for ashingled magnetic recording storage provider 424. The shingled magneticrecording storage bin 414 may determine where and how to store datawithin storage of the shingled magnetic recording storage provider 424,set what protocols to use, set what garbage collection technique to use,set thresholds for determining cold/hot data for the shingled magneticrecording storage provider 424, set what compression to use, setredundancy polices, set security policies, set what I/O access size touse, set what data format to use, determine how to reference/identifyparticular data, etc.

A high availability storage bin 416 may be generated for a highavailability storage provider 426 (e.g., two nodes configured accordingto a high availability configuration). The high availability storage bin416 may determine where and how to store data within storage of the highavailability storage provider 426, set what protocols to use, set whatgarbage collection technique to use, set thresholds for determiningcold/hot data for the high availability storage provider 426, set whatcompression to use, set redundancy polices, set security policies, setwhat I/O access size to use, set what data format to use, determine howto reference/identify particular data, etc.

In this way, the storage abstraction layer 406 can use the storage binsto individually manage different types of storage provided by thevarious storage providers. The storage abstraction layer 406 cangenerate a storage aggregate comprised of portions of storage from thevarious storage providers notwithstanding the storage providers hostingdifferent types of storage, using different data formats, referencingdata in different manners (e.g., physical block number, file name,offset, virtual block number, etc.) using different storage protocols,using different I/O access sizes, etc. The storage aggregate can beexposed up to the file system of the storage file system layer 404 as asingle storage container. In this way, the storage abstraction layer 406abstracts away the details of physically sending, storing, retrieving,and managing data across the storage providers (e.g., the file systemmay merely issue a write command to the storage aggregate, and thestorage abstraction layer 406 may select a particular storage bin to usefor selectively storing data of the write command to a particularstorage provider).

FIGS. 5A-5E illustrate examples of a system 500 for providing a storageabstraction layer 512 for a composite aggregate architecture. Thestorage abstraction layer 512 may be provided as an indirection layerbetween a file system 506 and a storage environment, as illustrated byFIG. 5A. The storage environment may be defined as storage providersaccessible to the storage abstraction layer 512, such as a solid statedrive storage provider 526, a hard disk drive storage provider 528, anobject storage provider 530 (e.g., a cloud storage provider hosted by athird party), and/or other local or remote storage providers.

The storage abstraction layer 512 may obtain characteristics of thestorage providers, such as I/O access sizes, latencies, communicationprotocols, indications as to whether storage is more suitable forcertain types of access (e.g., random access, sequential access,frequent access, infrequent access, etc.), how data isaddressed/referenced, availability (e.g., whether failover operation isprovided), redundancy, backup, garbage collection, etc.

The storage abstraction layer 512 may use the characteristics togenerate storage bins (e.g., configured with functionality, methods,policies, classes, etc.) used to manage storage of the storageproviders, such as a solid state drive storage bin 518, a hard diskdrive storage bin 520, an object storage bin 522, etc. A storage bin maybe configured to determine whether characteristics of data matchcharacteristics of a corresponding storage provider, and thus areeligible to be stored within storage of the corresponding storageprovider, otherwise, should be stored within storage of a differentstorage provider. The storage bin may be configured to determine whereand how to store data within the storage of the corresponding storageprovider. The storage bin may be configured with redundancy policyinformation, backup policy information, replication policy information,compression information, encryption information, deduplicationinformation, garbage collection information, access metrics used toidentify hot and cold data, what type of data is to be stored within thestorage of the corresponding storage provider (e.g., user data,metadata, frequently accessed data, infrequently accessed data,sequential data, random data, encrypted data, compressed data, redundantor backup data, etc.), and/or other functionality and policies toimplement for the storage of the corresponding storage provider. In thisway, the storage abstraction layer 512 comprises storage efficiencypreservation functionality 514, such as to preserve encryption,compression, deduplication, etc. of the file system 506.

The storage abstraction layer 512 may construct a storage aggregate 510from solid state drive storage of the solid state drive storage provider526, hard disk drive storage of the hard disk drive storage provider528, object storage of the object storage provider 530, and/or othertypes of storage of other storage providers (e.g., shingled magneticrecord storage, NVRAM, high availability storage providing by a highavailability node pair, locally attached storage, remotely attachedstorage, storage accessing through a NAS protocol, storage accessingthrough a SAN protocol, etc.). In this way, the storage aggregate 510 iscomposed from heterogeneous types of storage, and is exposed to the filesystem 506 as a single data container where the storage abstractionlayer 512 abstractions away the particulars of how and where data isstored and managed.

The file system 506 may provide a client 502 with access to the storageaggregate 510. Because the file system 506 views the storage aggregateas a single data container, the file system 506 may expose the storageaggregate 510 or a portion thereof to the client 502 as a single datacontainer (e.g., a single volume, a single LUN, etc.). In an example, afirst portion of the storage aggregate 510 may be exposed to the client502, and a second portion of the storage aggregate 510 may be exposed toa different client, and thus the file system 506 provides a second levelof indirection to the clients.

In an example, the file system 506 receives a write request 504 from theclient 502 to write data (A) 524 to the storage aggregate 510 (e.g., awrite request 504 directed by the client 502 to a volume or LUN exportedfrom the storage aggregate 510 by the file system 506 to the client502). The file system 506 may generate a write operation 508 to writethe data (A) 524 to the storage aggregate 510. The storage abstractionlayer 512 may intercept the write operation 508 and determine datacharacteristics of the data (A) 524 (e.g., is the data (A) 524frequently accessed data, user data, metadata, random data, sequentialdata, etc.). The storage abstraction layer 512 may determine that thedata characteristics of the data (A) 524 more closely matchcharacteristics of the solid state drive storage provider 526.Accordingly, the solid state drive storage bin 518 may be used todetermine where and how to storage the data (A) 524 within solid statedrive storage of the solid state drive storage provider 526.

The storage abstraction layer 512, such as individual storage bins, maymaintain a log 516 (e.g., or a log per storage bin) into which aparticular type of data is accumulated so that accumulated data can bemoved between storage of storage providers (e.g., cold data may beaccumulated into a first log so that the cold data can be moved to astorage provider more suited for storing cold data; hot data may beaccumulated into a second log so that the hot data can be moved to astorage provider more suited for storing hot data; sequentially accesseddata may be accumulated into a third log so that the sequentiallyaccessed data can be moved to a storage provider more suited for storingsequentially accessed data; randomly accessed data may be accumulatedinto a fourth log so that the randomly accessed data can be moved to astorage provider more suited for storing randomly accessed data; userdata may be accumulated into a fifth log so that the user data can bemoved to a storage provider more suited for user data; metadata may beaccumulated into a sixth log so that the metadata can be moved to astorage provider more suited for metadata; etc.).

In an example, data (X) may be accumulated into the log 516 based upon afrequency of access to data (X) falling below a threshold set by aparticular storage bin for a particular storage provider. For example,upon the storage bin determining that the data (X) is accessed below thethreshold, the data (X) may be accumulated from storage of the storageprovider into the log 516 of that storage bin. Once a threshold amountof cold data is accumulated within the log 516, the accumulated colddata may be sent to a target storage provider better suited for colddata. Compression, deduplication, encryption, data formatting (e.g.,storing data blocks into a storage object), and/or other storageoperations may be performed upon the accumulated cold data before beingsent to the target storage provider.

FIG. 5B illustrates the storage abstraction layer 512 determining that afrequency of access to the data (A) 524 within the solid state drivestorage of the solid state drive storage provider 526 has fallen below athreshold set by the solid state drive storage bin 518 for the solidstate drive storage provider 526. Accordingly, a storage location atwhich the data (A) 524 is stored within the solid state drive storagemay be designated 540 (e.g., by the solid state drive storage bin 518)for garbage collection to later be freed so that new data can be storedwithin the storage location. The data (A) 524 may be extracted from thesolid state drive storage by the solid state drive storage bin 518 andaccumulated into the log 516 maintained by the solid state drive storagebin 518. In this way, cold data managed by the solid state drive storagebin 518 is accumulated into the log 516. It may be appreciated that anytype of data may be accumulated into a log for migration of such datafrom a particular storage provider to a different storage provider(e.g., cold data, hot data, user data, metadata, randomly accessed data,redundant data, etc.).

FIG. 5C illustrates the storage abstraction layer 512, such as the solidstate drive storage bin 518, determining that a threshold amount of data(e.g., cold data) has been accumulated into the log 516. Accordingly, astorage object 550 (e.g., a file, a blob, a range of blocks, a datastructure, a data container, an object, etc.) may be generated tocomprise the data (X), the data (A) 524, and/or other data that wasaccumulated into the log 516. Before generating the storage object 550,the storage abstraction layer 512 may format the data (e.g., the datamay be formatted into a type of storage object used by the objectstorage provider 530 for storing data), deduplicate the data, encryptthe data, compress the data, etc. In this way, the storage object 550 isa single data container into which multiple related or unrelated datamay be stored (e.g., the data (X) may be metadata and the data (A) 524may be part of a client file).

The object storage bin 522 may send the storage object 550 to the objectstorage provider 530 that stores the storage object 550 within objectstorage provided by the object storage provider 530 and managed by theobject storage bin 522. The object storage bin 552 may populate anobject metafile with an object identifier of the storage object 550 andoffsets of data stored into the storage object 550.

FIG. 5D illustrates the client 502 submitting an access request 560 tothe file system 506 for accessing the data (A) 560. In one example, theclient 502 and/or the file system 506 are unaware of the location of thedata (A) 524 (e.g., the file system 506 is merely aware of the notion ofthe storage aggregate 510 as a single data container). Accordingly, thefile system 506 submits an access operation 562 to the storage aggregate510, which is intercepted by the storage abstraction layer 512. In anexample, the client 502 and/or the file system 506 may address the data(A) 524 by a physical volume block number or any other identifier (e.g.,a file identifier, a virtual block number, etc.).

The storage abstraction layer 512 determines that the data (A) 524 iscurrently managed by the object storage bin 522 and is stored withinobject storage of the object storage provider 530. Accordingly, theobject storage bin 522 may query the object metafile using the physicalvolume block number to identify the object identifier of the storageobject 550 and an offset of the data (A) 524 within the storage object550. The object identifier and the offset may be used by the objectstorage bin 522 to provide access 564 to the data (A) 524 within thestorage object 550 stored within the object storage by the objectstorage provider 530.

FIG. 5E illustrates the solid state drive storage bin 518 performinggarbage collection 570 upon the solid state drive storage of the solidstate drive storage provider 526 (e.g., independent of any garbagecollection and/or reference count tracking provided by the file system506 and/or the solid state drive storage provider 526). Accordingly, thesolid state drive storage bin 518 may free 572 the storage locationdesignated 540 for garbage collection (e.g., the old/stale location ofthe data (A) 524).

Still another embodiment involves a computer-readable medium comprisingprocessor-executable instructions configured to implement one or more ofthe techniques presented herein. An example embodiment of acomputer-readable medium or a computer-readable device that is devisedin these ways is illustrated in FIG. 6, wherein the implementation 600comprises a computer-readable medium 608, such as a compactdisc-recordable (CD-R), a digital versatile disc-recordable (DVD-R),flash drive, a platter of a hard disk drive, etc., on which is encodedcomputer-readable data 606. This computer-readable data 606, such asbinary data comprising at least one of a zero or a one, in turncomprises a processor-executable computer instructions 604 configured tooperate according to one or more of the principles set forth herein. Insome embodiments, the processor-executable computer instructions 604 areconfigured to perform a method 602, such as at least some of theexemplary method 300 of FIG. 3, for example. In some embodiments, theprocessor-executable computer instructions 604 are configured toimplement a system, such as at least some of the exemplary system 400 ofFIG. 4 and/or at least some of the exemplary system 500 of FIG. 5A-5E,for example. Many such computer-readable media are contemplated tooperate in accordance with the techniques presented herein.

It will be appreciated that processes, architectures and/or proceduresdescribed herein can be implemented in hardware, firmware and/orsoftware. It will also be appreciated that the provisions set forthherein may apply to any type of special-purpose computer (e.g., filehost, storage server and/or storage serving appliance) and/orgeneral-purpose computer, including a standalone computer or portionthereof, embodied as or including a storage system. Moreover, theteachings herein can be configured to a variety of storage systemarchitectures including, but not limited to, a network-attached storageenvironment and/or a storage area network and disk assembly directlyattached to a client or host computer. Storage system should thereforebe taken broadly to include such arrangements in addition to anysubsystems configured to perform a storage function and associated withother equipment or systems.

In some embodiments, methods described and/or illustrated in thisdisclosure may be realized in whole or in part on computer-readablemedia. Computer readable media can include processor-executableinstructions configured to implement one or more of the methodspresented herein, and may include any mechanism for storing this datathat can be thereafter read by a computer system. Examples of computerreadable media include (hard) drives (e.g., accessible via networkattached storage (NAS)), Storage Area Networks (SAN), volatile andnon-volatile memory, such as read-only memory (ROM), random-accessmemory (RAM), electrically erasable programmable read-only memory(EEPROM) and/or flash memory, compact disk read only memory (CD-ROM)s,CD-Rs, compact disk re-writeable (CD-RW)s, DVDs, cassettes, magnetictape, magnetic disk storage, optical or non-optical data storage devicesand/or any other medium which can be used to store data.

Although the subject matter has been described in language specific tostructural features or methodological acts, it is to be understood thatthe subject matter defined in the appended claims is not necessarilylimited to the specific features or acts described above. Rather, thespecific features and acts described above are disclosed as exampleforms of implementing at least some of the claims.

Various operations of embodiments are provided herein. The order inwhich some or all of the operations are described should not beconstrued to imply that these operations are necessarily orderdependent. Alternative ordering will be appreciated given the benefit ofthis description. Further, it will be understood that not all operationsare necessarily present in each embodiment provided herein. Also, itwill be understood that not all operations are necessary in someembodiments.

Furthermore, the claimed subject matter is implemented as a method,apparatus, or article of manufacture using standard application orengineering techniques to produce software, firmware, hardware, or anycombination thereof to control a computer to implement the disclosedsubject matter. The term “article of manufacture” as used herein isintended to encompass a computer application accessible from anycomputer-readable device, carrier, or media. Of course, manymodifications may be made to this configuration without departing fromthe scope or spirit of the claimed subject matter.

As used in this application, the terms “component”, “module,” “system”,“interface”, and the like are generally intended to refer to acomputer-related entity, either hardware, a combination of hardware andsoftware, software, or software in execution. For example, a componentincludes a process running on a processor, a processor, an object, anexecutable, a thread of execution, an application, or a computer. By wayof illustration, both an application running on a controller and thecontroller can be a component. One or more components residing within aprocess or thread of execution and a component may be localized on onecomputer or distributed between two or more computers.

Moreover, “exemplary” is used herein to mean serving as an example,instance, illustration, etc., and not necessarily as advantageous. Asused in this application, “or” is intended to mean an inclusive “or”rather than an exclusive “or”. In addition, “a” and “an” as used in thisapplication are generally be construed to mean “one or more” unlessspecified otherwise or clear from context to be directed to a singularform. Also, at least one of A and B and/or the like generally means A orB and/or both A and B. Furthermore, to the extent that “includes”,“having”, “has”, “with”, or variants thereof are used, such terms areintended to be inclusive in a manner similar to the term “comprising”.

Many modifications may be made to the instant disclosure withoutdeparting from the scope or spirit of the claimed subject matter. Unlessspecified otherwise, “first,” “second,” or the like are not intended toimply a temporal aspect, a spatial aspect, an ordering, etc. Rather,such terms are merely used as identifiers, names, etc. for features,elements, items, etc. For example, a first set of information and asecond set of information generally correspond to set of information Aand set of information B or two different or two identical sets ofinformation or the same set of information.

Also, although the disclosure has been shown and described with respectto one or more implementations, equivalent alterations and modificationswill occur to others skilled in the art based upon a reading andunderstanding of this specification and the annexed drawings. Thedisclosure includes all such modifications and alterations and islimited only by the scope of the following claims. In particular regardto the various functions performed by the above described components(e.g., elements, resources, etc.), the terms used to describe suchcomponents are intended to correspond, unless otherwise indicated, toany component which performs the specified function of the describedcomponent (e.g., that is functionally equivalent), even though notstructurally equivalent to the disclosed structure. In addition, while aparticular feature of the disclosure may have been disclosed withrespect to only one of several implementations, such feature may becombined with one or more other features of the other implementations asmay be desired and advantageous for any given or particular application.

What is claimed is:
 1. A method comprising: generating a storageaggregate as a single container constructed from first storage havingfirst characteristics and second storage having second characteristics;selectively storing first data of a file system into the first storagebased upon the first characteristics and second data of the file systeminto a storage object within the second storage based upon the secondcharacteristics, wherein the file system can access to the storageaggregate as the single container within which the file system storesdata; receiving a request, specifying a physical volume block number, toaccess the second data; and querying a metafile, mapping physical volumeblock numbers to object identifiers of storage objects and offsetswithin the storage objects, using the physical volume block number toidentify an object identifier of the storage object and an offset of thesecond data within the storage object for processing the request.
 2. Themethod of claim 1, wherein the first storage comprises local storagehosted by a node that provides access to locally attached storagedevices as the local storage.
 3. The method of claim 2, wherein thesecond storage comprises cloud storage hosted remote to the node.
 4. Themethod of claim 1, comprising: populating the metafile with an entrycomprising an indicator that the data is stored within a first storageobject, a first object identifier of the first storage object, and afirst offset of the data within the first storage object.
 5. The methodof claim 1, comprising: tracking reference counts of references to datawithin the first storage.
 6. The method of claim 5, comprising: freeingdata, with reference counts of zero, from the first storage.
 7. Themethod of claim 1, comprising: accessing the first data in the firststorage using a first I/O size.
 8. The method of claim 7, comprising:accessing the second data within the second storage using a second I/Osize different than the first I/O size.
 9. A non-transitory machinereadable medium comprising instructions for performing a method, whichwhen executed by a machine, causes the machine to: generate a storageaggregate constructed from first storage having first characteristicsand second storage having second characteristics; selectively storefirst data of a file system into the first storage based upon the firstcharacteristics and second data of the file system into a storage objectwithin the second storage based upon the second characteristics, whereinthe file system can access to the storage aggregate as the singlecontainer within which the file system stores data; and process arequest, specifying a physical volume block number, to access the seconddata, wherein a metafile, mapping physical volume block numbers toobject identifiers of storage objects and offsets within the storageobjects, is queried using the physical volume block number to identifyan object identifier of the storage object and an offset of the seconddata within the storage object for processing the request.
 10. Thenon-transitory machine readable medium of claim 9, wherein theinstructions cause the machine to: selectively store target data of awrite request from the file system into a first storage location of thefirst storage based upon a data characteristic of the target datacorresponding to the first characteristics of the first storage.
 11. Thenon-transitory machine readable medium of claim 10, wherein theinstructions cause the machine to: store data of an overwrite request,targeting the target data, into a second storage location as new data,wherein the second data is marked for garbage collection.
 12. Thenon-transitory machine readable medium of claim 10, wherein theinstructions cause the machine to: track reference counts of referencesto data within the first storage.
 13. The non-transitory machinereadable medium of claim 12, wherein the instructions cause the machineto: free data, with reference counts of zero, from the first storage.14. The non-transitory machine readable medium of claim 9, wherein theinstructions cause the machine to: selectively store data within eitherthe first storage or the second storage based upon whether the data hasa sequential access characteristic or a random access characteristic.15. A computing device comprising: a memory comprising machineexecutable code; and a processor coupled to the memory, the processorconfigured to execute the machine executable code to cause the processorto: generate a storage aggregate as a single container constructed fromfirst storage having first characteristics and second storage havingsecond characteristics; selectively store first data into the firststorage based upon the first characteristics and second data into astorage object within the second storage based upon the secondcharacteristics; receive a request, specifying a physical volume blocknumber, to access the second data; and query a metafile, mappingphysical volume block numbers to object identifiers of storage objectsand offsets within the storage objects, using the physical volume blocknumber to identify an object identifier of the storage object and anoffset of the second data within the storage object for processing therequest.
 16. The computing device of claim 15, wherein the machineexecutable code causes the processor to: selectively store the datawithin either the first storage or the second storage based upon whetherthe data has a user data access characteristic or a metadata accesscharacteristic.
 17. The computing device of claim 15, wherein themachine executable code causes the processor to: selectively store thedata within either the first storage or the second storage based uponwhether the data has a frequently accessed characteristic or aninfrequently accessed characteristic.
 18. The computing device of claim15, wherein the machine executable code causes the processor to: providea file system with access to the storage aggregate, wherein the filesystem is hosted across multiple nodes of a computing environment. 19.The computing device of claim 15, wherein the first storage supports afirst I/O size and the second storage supports a second I/O sizedifferent than the first I/O size.
 20. The computing device of claim 19,wherein a file system supports the first I/O size, wherein the secondI/O size is unsupported by the file system, and wherein the file systemis provided with access to the storage aggregate.